Electronic enthusiasts that need to measure angles on their robotic arm or other projects may be interested in a new proximity sensor that has been created by William Moore called the Protractor. The ...

Forget hunting for a tape measure or a protractor. Use your Android phone camera and sensors to handle different types of measurements easily.

This is our second activity that requires the use of a smartphone or tablet. Please let us know what you think. E-mail editors@sciam.com with feedback about the use of technology in this—and ...

We independently review everything we recommend. We may get paid to link out to retailer sites, and when you buy through our links, we may earn a commission. Learn more› By Ray Aguilera, Ganda ...